package com.albert.eurekaproducer.interceptor;

import com.albert.eurekaproducer.config.AccessToken;
import com.albert.eurekaproducer.config.PassToken;
import com.albert.eurekaproducer.controller.UserInfoController;
import com.auth0.jwt.JWT;
import com.auth0.jwt.JWTVerifier;
import com.auth0.jwt.algorithms.Algorithm;
import com.auth0.jwt.exceptions.JWTDecodeException;
import com.auth0.jwt.exceptions.JWTVerificationException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.env.Environment;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.lang.reflect.Method;

public class AuthenticationInterceptor implements HandlerInterceptor {
    private final static Logger logger = LoggerFactory.getLogger(AuthenticationInterceptor.class);

    @Autowired
    private Environment environment;

    @Override
    public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object object) throws Exception {
        String token = httpServletRequest.getHeader("JWT-TOKEN");// 从 http 请求头中取出 token
        // 如果不是映射到方法直接通过
        if (!(object instanceof HandlerMethod)) {
            return true;
        }
        HandlerMethod handlerMethod = (HandlerMethod) object;
        Method method = handlerMethod.getMethod();
        //检查是否有passtoken注释，有则跳过认证
        if (method.isAnnotationPresent(PassToken.class)) {
            PassToken passToken = method.getAnnotation(PassToken.class);
            if (passToken.required()) {
                return true;
            }
        }
        //检查有没有需要用户权限的注解
        if (method.isAnnotationPresent(AccessToken.class)) {
            AccessToken userLoginToken = method.getAnnotation(AccessToken.class);
            if (userLoginToken.required()) {
                // 执行认证
                if (token == null) {
                    logger.error("没有无token值，无权限请求");
                    throw new RuntimeException("无token，没有权限");
                }
                // 获取 token 中的 ak
                String ak;
                try {
                    ak = JWT.decode(token).getAudience().get(0);
                } catch (JWTDecodeException j) {
                    logger.error("没有ak值，无权限请求");
                    throw new RuntimeException("401");
                }

                String sk = environment.getProperty("SECRETKEY." + ak);
                if (sk == null) {
                    throw new RuntimeException("401");
                }
                // 验证 token
                JWTVerifier jwtVerifier = JWT.require(Algorithm.HMAC256(sk)).build();
                try {
                    jwtVerifier.verify(token);
                } catch (JWTVerificationException e) {
                    logger.error("token校验失败，无权限请求,token={} , ak={}", token, ak);
                    throw new RuntimeException("401");
                }
                logger.info("token校验完成,token={} , ak={} ", token, ak);
                return true;
            }
        }
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest httpServletRequest,
                           HttpServletResponse httpServletResponse,
                           Object o, ModelAndView modelAndView) throws Exception {

    }

    @Override
    public void afterCompletion(HttpServletRequest httpServletRequest,
                                HttpServletResponse httpServletResponse,
                                Object o, Exception e) throws Exception {
    }
}
